From 25f920ebcb593bbff242165de3d10f8d29fae19b Mon Sep 17 00:00:00 2001
From: maddavo <1432875+maddavo@users.noreply.github.com>
Date: Thu, 10 Sep 2026 23:21:45 +1000
Subject: [PATCH 1/2] Fix heat loop list scroll content

---
 CHANGELOG.md                        | 1 +
 Source/UI/ToolbarUI/ToolbarLoops.cs | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3267421..6da6f60 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 ## Unreleased
 - Improved performance
   - Color animations no longer update all materials when they haven't changed.
+- Fixed the heat-loop list scroll content not expanding when a vessel has more loops than fit in the viewport.
 
 ## 0.9.1 - 2026-05-12
 - Fixed memory leaks from dangling event handlers.
diff --git a/Source/UI/ToolbarUI/ToolbarLoops.cs b/Source/UI/ToolbarUI/ToolbarLoops.cs
index a66a2a0..6ef37ef 100644
--- a/Source/UI/ToolbarUI/ToolbarLoops.cs
+++ b/Source/UI/ToolbarUI/ToolbarLoops.cs
@@ -135,6 +135,11 @@ protected void RecalculatePanelPositionData()
       Utils.Log($"Source data: buttonYOffsetFromTop={buttonYOffsetFromTop }, loopPanelMaxHeight={loopPanelMaxHeight} widgetTotalHeight={widgetTotalHeight}", LogType.UI);
       //loopPanelWidgets.Count * 68f + vlg.padding.top+vlg.padding.bottom+ 3f+7.5f*(loopPanelWidgets.Count-1);
       loopPanelRootRect.SetSizeWithCurrentAnchors(RectTransform.Axis.Vertical, loopPanelMaxHeight);
+      // The ScrollRect content must contain the complete list.  Previously only
+      // the viewport was resized, leaving the content at its prefab height when
+      // more loops were added than could be shown at once.  That made some loop
+      // widgets unreachable or appear to be missing from the list.
+      loopPanelScrollRootRect.SetSizeWithCurrentAnchors(RectTransform.Axis.Vertical, widgetTotalHeight);
       loopPanelScrollViewportRect.anchorMin = loopPanelScrollBackground.anchorMin = new Vector2(0, 0);
       loopPanelScrollViewportRect.anchorMax = loopPanelScrollBackground.anchorMax = new Vector2(1, 0);
       loopPanelScrollCarat.anchorMin = new Vector2(0, 1);

From 6237ab6bff6211ffa2bab10228785eed407f0f32 Mon Sep 17 00:00:00 2001
From: maddavo <1432875+maddavo@users.noreply.github.com>
Date: Thu, 10 Sep 2026 23:31:49 +1000
Subject: [PATCH 2/2] Keep heat loop widgets ordered by ID

---
 Source/UI/ToolbarUI/ToolbarLoops.cs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Source/UI/ToolbarUI/ToolbarLoops.cs b/Source/UI/ToolbarUI/ToolbarLoops.cs
index 6ef37ef..6bbe9d5 100644
--- a/Source/UI/ToolbarUI/ToolbarLoops.cs
+++ b/Source/UI/ToolbarUI/ToolbarLoops.cs
@@ -120,6 +120,15 @@ void PollLoopWidgets(SystemHeatSimulator simulator)
           RecalculatePanelPositionData();
         }
       }
+
+      // Heat loops are discovered by walking vessel parts, so their creation
+      // order is not guaranteed to match their numeric IDs.  Keep the content
+      // order stable and predictable for the player.
+      loopPanelWidgets.Sort((left, right) => left.TrackedLoopID.CompareTo(right.TrackedLoopID));
+      for (int i = 0; i < loopPanelWidgets.Count; i++)
+      {
+        loopPanelWidgets[i].transform.SetSiblingIndex(i);
+      }
     }
     protected void RecalculatePanelPositionData()
     {